1. Field of the Invention
This invention relates to rotary-wing vehicles and in particular to rotary-wing toy helicopters.
2. Description of Related Art
A helicopter typically has two main rotor blades that are connected through a drive shaft to an engine. The air deflected downwards due to the spinning of the main rotor blades provides the lilting power. Rotor blades at the tail of the helicopter are directed in the horizontal plane to provide the anti-torque power that is required to prevent the helicopter from rotating due to the spinning main rotor blades. Changing the main rotor blades attack angle provides horizontal motion according to pilot's commands.
Sikorsky and Kamov first introduced a helicopter with two counter-rotating main rotors on a common axis. Eliminating the need for tail rotor blades, the counter-rotating blades provide higher maneuverability and stability.
There are various kinds of toy helicopters known in the art, some incorporating counter rotating rotors on a common axis. Most toy helicopters feature a form that has the appearance of a helicopter. A toy helicopter featuring a form that has the appearance of a plane and, when in flight, can appear to be a plane doing acrobatic stunts is not found in the prior art.